Can the reason for the pursuit of knowledge be anything other than self-interest? I have a hard time beliving anything else, please prove me wrong...

Maybe there is no reason to prove you wrong. I think self interest is why we do everything, and I can't see anything wrong with that. It is well-developed and fulfilled people who both enjoy life the most and contribute the most to others. Every kind of sincere act of helping others would not be done if the person doing didn't get some sort of good feeling from it. Can you imagine anybody helping others if every time one did it made one feel like crap?

I think it is a common mistake people make to confuse selfishness with healthy self interest. The selfish act is one where a person pursues his own desires and needs without respect for fact that this planet has to be shared with others, all of whom are also pursuing their own desires and needs.

So I hope you do become as knowledgable as possible because everyone can benefit from that if you do it respectfully sharing the world's resources.

I think it is a common mistake people make to confuse selfishness with healthy self interest.

Absolutely!

I would give my life to make things better for humanity in general. While that may not appear as self-interest it is. But it certainly couldn't be seen as selfish.

Now keep in mind here that I'm talking about making things before for humanity in general. I'm not talking about being a martyr for a cause. In that case it's quite possible that the "cause" I would be dying for could indeed be a selfish cause. So being a martyr in general isn't automatically selfless, on the contrary, it could be extremely selfish or arrogant.

Studying knowledge for the sake of improving medical science can surely be scene as a selfless cause. Although it could also be pursued for the purely selfish reasons of personal fame and fortune too.

Learning about our world in general to make it a better place for everyone is certainly not selfish. Especially if this includes a desire to protect the environment and all living creatures.

I don't believe that the pursuit of knowledge in and of itself is selfish. But a person could certainly pursue knowledge for selfish reasons.

But yes, in terms of pure self-interest (not selfishness) why would any creature do anything that they had no interest in?

One way I tried to explain it to one of my kids a few years ago was something like this;

We all have a level of comfort. lets say on a scale from 1 to 10 my comfort zone is in the range of 4.5 to 5.5. Below 4.4 I don't feel so good. But above 5.5 I start feeling really good. Now, if I spend to much time above or below my comfort zone, my comfort zone begins to adjust to a new level up or down depending on where i'm at most of the time. This is of course due to our ability to adapt to our situation. And this is why stimulates eventually lose there effect.

Now, based on this idea, I think every single action we take is initiated by a fundamental desire to feel better in the future.